Table 5.

Correlation between sleep disturbance/use of sleeping medication/daytime functioning with the total duration of sleep and the self-rated overall sleep quality.

	Total duration of sleep	Overall sleep quality
Sleep disturbance:
Frequency of breathing difficulty	-0.218∗	0.082
Frequency of coughing or snoring loudly	-0.106	-0.125
Frequency of pain	-0.222∗	0.150
Use of sleeping medication:
Frequency of taking sleeping medication	-0.215∗	-0.167
Daytime functioning:
Frequency of difficulty in staying awake during the day	-0.333∗∗	-0.321∗∗
Keeping up enough enthusiasm to get things done	0.384∗∗	0.388∗∗

Correlation coefficients are presented in the above table ^∗ − p < 0.05, ^∗∗ − p < 0.01, and ^∗∗∗ − p < 0.001.